Enrichment of CpG island shore region hypermethylation in epigenetic breast field cancerization.

While changes in DNA methylation are known to occur early in breast carcinogenesis and the landscape of breast tumour DNA methylation is profoundly altered compared with normal tissue, there have been limited efforts to identify DNA methylation field cancerization effects in histologically normal breast tissue adjacent to tumour. Matched tumour, histologically normal tissue of the ipsilateral breast (ipsilateral-normal), and histologically normal tissue of the contralateral breast (contralateral-normal) were obtained from nine women undergoing bilateral mastectomy. Laser capture microdissection was used to select epithelial cells from normal tissue, and neoplastic cells from tumour for genome-scale measures of DNA methylation with the Illumina HumanMethylationEPIC array. We identified substantially more CpG loci that were differentially methylated between contralateral-normal and tumour (63,271 CpG loci q < 0.01), than between ipsilateral-normal and tumour (38,346 CpG loci q < 0.01). We identified differential methylation in ipsilateral-normal relative to contralateral-normal tissue (9,562 CpG loci p < 0.01). In this comparison, hypomethylated loci were significantly enriched for breast cancer-relevant transcription factor binding sites including those for ESR1, FoxA1, and GATA3 and hypermethylated loci were significantly enriched for CpG island shore regions. In addition, progression of shore hypermethylation was observed in tumours compared to matched ipsilateral normal tissue, and these alterations tracked to several well-established tumour suppressor genes. Our results indicate an epigenetic field effect in surrounding histologically normal tissue. This work offers an opportunity to focus investigations of early DNA methylation alterations in breast carcinogenesis and potentially develop epigenetic biomarkers of disease risk. ABBREVIATIONS: DCIS: ductal carcinoma in situ; GO: gene ontology; OR: odds ratio; CI: confidence interval; TFBS: transcription factor binding site; LOLA: Locus Overlap Analysis.

DNA methylation in breast cancers: Differences based on estrogen receptor status and recurrence.

DNA methylation plays a role in the etiology of primary breast cancers. We analyzed paired primary and second breast tumors to elucidate the role of methylation in recurrence. Methylation profiles from paired primary and second breast tumors of 23 women were assessed using the HumanMethylation450 BeadChip. Twelve women had estrogen receptor positive (ERpos) primary and second tumors, five had estrogen receptor negative (ERneg) primary and second tumors, and six had an ERpos primary tumor but an ERneg second tumor. Stratifying tumors by occurrence revealed that the greater methylation previously associated with ERpos tumors, is more pronounced in primary tumors than in second tumors. Further, ERneg second tumors are more methylated than ERpos second tumors among women who had ERpos primary tumors. Pathway analyses using gene lists generated from comparisons of methylation in ERpos primary tumors from the paired sets with ERpos tumors from six women without recurrences, identified differences between groups based on the ER status of the second tumor. Hypermethylated genes of significantly enriched pathways were differentially associated with survival. DNA methylation profiles of ERpos primary breast tumors support the development and use of tumor methylation profiles for stratifying women with breast cancer both for prognosis and therapy.

TROP2 methylation and expression in tamoxifen-resistant breast cancer.

BACKGROUND: The DNA methyltransferase 1 inhibitor, 5-Aza-2'-deoxycytidine (5-Aza-dC) is a potential treatment for breast cancer. However, not all breast tumors will respond similarly to treatment with 5-Aza-dC, and little is known regarding the response of hormone-resistant breast cancers to 5-Aza-dC. METHODS: We demonstrate that 5-Aza-dC-treatment has a stronger effect on an estrogen receptor-negative, Tamoxifen-selected cell line, TMX2-28, than on the estrogen receptor-positive, MCF7, parental cell line. Using data obtained from the HM450 Methylation Bead Chip, pyrosequencing, and RT-qPCR, we identified a panel of genes that are silenced by promoter methylation in TMX2-28 and re-expressed after treatment with 5-Aza-dC. RESULTS: One of the genes identified, tumor associated calcium signal transducer 2 (TACSTD2), is altered by DNA methylation, and there is evidence that in some cancers decreased expression may result in greater proliferation. Analysis of DNA methylation of TACSTD2 and protein expression of its product, trophoblast antigen protein 2 (TROP2), was extended to a panel of primary (n = 34) and recurrent (n = 34) breast tumors. Stratifying tumors by both recurrence and ER status showed no significant relationship between TROP2 levels and TACSTD2 methylation. Knocking down TACSTD2 expression in MCF7 increased proliferation however; re-expressing TACSTD2 in TMX2-28 did not inhibit proliferation, indicating that TACSTD2 re-expression alone was insufficient to explain the decreased proliferation observed after treatment with 5-Aza-dC. CONCLUSIONS: These results illustrate the complexity of the TROP2 signaling network. However, TROP2 may be a valid therapeutic target for some cancers. Further studies are needed to identify biomarkers that indicate how TROP2 signaling affects tumor growth and whether targeting TROP2 would be beneficial to the patient.

Isolated pericardial and intracardiac hydatidosis: presentation as congestive cardiac failure and fatal pulmonary embolism.

Localization of hydatid cysts in the heart is a rare phenomenon, with an incidence of 0.5-2%. In almost half these cases, the heart is the sole organ to be involved. We report a case of massive pericardial hydatidosis in a female patient who presented with features of congestive cardiac failure. Cysts in the endocardium of right side of the heart resulted in fatal pulmonary embolism.

Isolated infective endocarditis of the pulmonary valve: an autopsy analysis of nine cases.

INTRODUCTION: Infective endocarditis (IE) of the pulmonary valve is uncommon and usually occurs in conjunction with tricuspid and/or left-sided valvular endocarditis. There have been only sporadic reports of isolated pulmonary valvular infective endocarditis (PVIE). This report documents the pathological features of nine such cases at autopsy. METHODS: Among 155 cases of IE encountered in a 14-year period, we selected nine cases that had isolated PVIE for analysis. The clinical records were reviewed for the patient demographics, presence or absence of underlying cardiac disease or other predisposing factors, and modes of presentation; these were correlated with the relevant investigations. A detailed study of the heart was done in all with special attention to the pulmonary valve morphology. RESULTS: The nine cases of isolated PVIE formed 5.8% of the IE cases, seen in six males and three females, largely adults. Seven patients (77.8%) had admissions for about 24 h. Hospital admission was sought for mainly progressive shortness of breath (66.7%) and fever (44.4%). Congenital heart disease was seen in seven (77.8%); two (an infant and an adult) had normal hearts. A single blood sample for blood culture in two patients was negative. Two-dimensional echocardiography, performed in eight, revealed vegetations on the pulmonary valve in four. The pulmonary valve was tricuspid in six cases, bicuspid in two, and unicuspid in one. The vegetations (active in three, active and healing in two, healed in four) were accompanied by concomitant thickening, shortening, perforations, or complete destruction of the cusps. Involvement of the right ventricular outflow tract or the main pulmonary artery was identified in five hearts. Five patients (55.6%) developed pulmonary complications, related to the endocarditis. CONCLUSIONS: Detection of PVIE, especially the isolated type, may be underdiagnosed. This condition should be kept in mind during evaluation of patients especially with cardiac anomalies, who present with fever, prominent respiratory symptoms, and negative blood cultures.